g0ozs

Dear All Some photos from GB2CRF are now on line at: http://www.g0ozs.org/clansman/GB2CRF/subalbum_1.html We worked about 25 other stations, mostly on 7MHz from the RT320 outdoors Regards Iain

Hi Arnie & Debbie Hopefully I will also be at W&P as a day visitor - should be able to see your 432 and work you across the field then! Mike M1CCF and friends usually operate an HF station from a tent at the end of the fleamarket beside the main road - he usually has various larkspur and clansman accessories for sale as well! Iain 73 deG0OZS

Arnie If you need C type plugs to fit it they are available from GTEN98 (aka PTS Norfolk) and E7MKG on e-Bay - I have no connection other than a satisfied customer. The item numbers are 360012698904 from E7MKG to fit 6mm / RG58 cable and GTEN98 has nearly the full range in their e-bay shop for 1/2 inch (UR67) cable. See items 120743739679, 120889929947, 120786269604, 120743751481, 120897388775, and ready made cables 110735750335 Hope this helps Iain

Marmon My SUMB was stencilled TP50 (50psi) above the wheel arches for the original 10.5R20 Michelins - I have always stuck to that. Given that I am not loading the truck much over 3.5 tonnes that is probably a bit firm. As an aside, did you use the original SUMB wheels with the 12x20s ? Regards Iain

I agree - you are probably too close - I expect to start on 3.615 MHz AM or 7.187 MHz AM subject to conditions and interference before moving up to 14MHz to hunt as many other countries as I can. I will PM you my mobile and direct e-mail so you can ask for an update on our working frequency during the day. What callsign should we listen out for ? Regards Iain (apologies for hijacking the Portsmouth thread)

Hi Probably mostly 14MHz as the 322 is unconverted so USB only - we may try 3.615MHz AM first thing around 11am - our callsign will be GB2CRF There is a topic for it somewhere under future events with no recent replies, if you want to continue there... Regards Iain

Jon I can't help with a vehicle but if you have access to an Amateur radio station we will be happy to give you a call from a similar event here at the Suffolk Aviation Heritage group near Ipswich on the Sunday - we hope to have most of the Clansman radios that went South operational on the day Regards & best wishes for your event Iain

Andy I have also been told by someone who used the set in service that it was possible to use the 20W amp with the whip antenna by using a pre-tuned SURF. The SURF is really a co siting band pass filter rather than an antenna tuner but it at least provides the transition from BNC coax to whip base required. It needs to be pre tuned at low power because it will otherwise block/absorb the output if off frequency and something is going to get hot! (bearing in mind it is a 4w SURF and a 20W amp!) It's also worth noting that the 20w amp is actually likely to give a lot more than 20w on a decent or float charged battery - of the dozen or so I tested and sold on e-Bay in 2010 all were good for at least 25w on 1 band and some managed up to 28w! The GSA (or a TUAAM/ARFAT combination connected to the 352 via an initiate box) would be a better choice because the antenna is properly tuned - by using the right number of elements in the GSA or by the TUAAM acting as an antenna tuning unit) whereas the whips are a compromise that are only efficient on the frequency where they are 1/4 wave long. Since inefficient antennas reflect power they can't radiate back to the source the 20w amp will likely get hot sooner if nothing else when using an unmatched whip! I've also used the 352 with an EVHF pineapple quite happily although I wonder if the extra height of an 8 or 11m mast compensates for the inherent loss in the matching network inside the pineapple base - on all my test gear they show as way worse matched than a GSA set to the right length. I suspect that the elevated GSA with 20w is actually the most efficient of the lot at getting power radiated ! Regards Iain

Andy You asked ... Frequency hopping and spread spectrum are the modulation methods used by modern digital radios to avoid detection and interception. Traditional combat net radios operated on a fixed channel for hours on end and were fairly easy to intercept by an enemy with a scanning receiver and even locate by taking bearings on the signal (that was the purpose of the Land Rover 101 Vampire) leading to jamming or artillery and air strikes on the transmitter location. This leads to two basic requirements - digital encryption to protect the speech content from being overheard and rapid frequency (channel) changes to avoid detection in the first place. Modern military radios avoid interception by use of digitally encoded speech that can then be encrypted. The Clansman DMU and BID solved that problem at least for fixed and vehicle stations but the equivalent function is embedded in all modern military radios. The requirement to change frequency is met by either spreading the signal over a wide bandwidth so it is hard to detect and decode (true spread spectrum as used in the Marconi/Selex PRR and WiFi) or by frequency hopping over a wide range of channels in a preset sequence shared by all stations on a particular net. Hopping was used by the US SINGCARS from the mid 1980s and Marconi, Plessey and Racal made similar sets for export (which might have ended up in Ferrets at that time?) but the British Army had to wait until about 2005 for wholesale replacement of Clansman with Bowman. True Bowman sets are basically fast frequency hoppers (10 or more channel changes per second) with encrypted digital modulation and integrated data terminals. The SELEX PRR is a separate project providing personal radio using different technology. Returning to the subject (sort of) did any ferrets last into the Bowman era ? I would have thought that there would be insufficient space for a secure Clansman installation with 2 radios but was there a configuration with one RT353 and DMU ? Regards Iain

The choices of frequency and modulation are independent of each other. It is only convention that ties VHF to FM and Medium Wave to AM. From an engineering viewpoint FM is optimal for short range interference free links and AM (or better SSB and morse code) for long range links subject to interference. VHF or very high frequency is 30 to 300MHz in most radio books. The military combat net radio VHF range is 30 to 80MHz nowadays and it was conventional to use frequency modulation from late WW2 until the rise of digital radios in the last 10 or 15 years. The MF (medium frequency) band 300KHz to 3MHz and HF (high frequency) bands 3 to 30MHz were conventionally used with various forms of morse code and amplitude modulation. SSB as seen on the Clansman RT320 and RT321 mode switches is basically a more efficient form of AM in which all the transmitted power carries speech information. These are not fundamental rules however - the aeronautical VHF bands use AM to this day, and radio amateurs use single sideband (SSB) on VHF for long range communication but FM on VHF for local chat. Conversely several Larkspur radios were designed to be able to use phase modulation on HF - although I believe the facility was a by product of their support for frequency shift keyed teleprinter modems and seldom used for speech. In terms of the Ferret there are others more knowledgeable than I (alien where are you?) but there were both mixed HF/VHF and dual VHF radio fits in both the Larkspur (1960s-70s) and Clansman (1980s-2000s) eras. I think the Clansman VHF fit was usually 1 x RT353 and 1 x RT352 - I'm not sure if there were different patrol and re-broadcast fits. The larkspur fit would have been a C42 and B47 I assume? Hope this helps a bit ? Regards Iain

Mark I am just south of Ipswich and have 4 tyres - without going out to check most or all are Michelins with the expected cracking, on 20 inch SUMB wheels. The new old stock unused Michelins I got from RR to replace them also have early signs of cracking even though either unused or hardly used so your suspicion is justified I think. If I remember right I last re - listed the older ones at £50 for each wheel and tyre without success so I guess the going rate is less than that for Michelin - I am open to offers. Lauren If you end up with any of the good tyres left after Mark's needs are met I am interested in a pair ... I think the Continentals are the only ones currently being sold new in the UK at least from when I have been researching what to do when all the "new old stock" Michelins are beyond use .. Regards Iain

Mark The SUMB wheels with used 10.5R20 Michelin tyres that I tried and failed to advertise on here a while back remain available http://hmvf.co.uk/forumvb/showthread.php?24041-4-off-10-5R20-Simca-Marmon-SUMB-wheels-with-used-tyres These were left over after I got new(er) ones from RR Motor services for the SUMB and have some superficial side wall cracking. Regards Iain

Dear All I have now been issued with the special event callsign GB2CRF ("Clansman Radio Falklands") for a station to be operated by the Felixstowe & District Amateur Radio Society at the Suffolk Aviation Heritage Society's museum at the former RAF Foxhall Heath on Sunday 6th May in support of the SAHS's "Falklands 30th Anniversary" event. It is hoped that the station will be on air from 11am until 4pm local time on the HF bands, 4m and 6m. HF frequencies will be determined by conditions on the day although we are likely to include 3.615MHz AM and 7.1875MHz USB at some point during the day. We will monitor 51.75MHz on 6m FM and 70.475MHz on 4m FM and would welcome HF spots called in on those frequencies (as the Clansman HF sets have frequency setting switches and it is a pain to tune the bands!). We will operate both a base and a field station on the museum site.The base station is expected to have an RT322 250-watt base station using the RAF Foxhall heath masts and a pair of RT353 VHF transceivers using ground spike or EVHF antennas for 4m and 6m. The field station is expected to have an RT320 HF and a RT352 VHF radio using Clansman field antennas. Depending on the space available other 1982 radio and telephone equipment may be on display as well. A special QSL card will be available via the RSGB Bureau to stations working GB2CRF on the 6th of May. I am not the event organiser - just sorting the radio side - but I understand that there is room for more vehicles and although 1982 UK or Argentine use is desirable there may now be some flexibility. PM me here for further details. Iain 73 de G0OZS

I have class VII MoT done at Capel Station Garage on the A12 just south of Ipswich for my SUMB (3460KG on V5). Iain

Hello and welcome Mike Hopefully i will see you and the MW at one of the events around Suffolk this summer Iain

Clive The full list of EMERS available to VMARS members is at http://www.moffatig.com/emers/restricted_document_index.htm You may also find that useful to index your archive for Clansman ? Regards Iain

Tankboy, Clive It's an "Interconnection Box, 3 Radio" used in the Clansman harness. there were two versions - black fronted originals used with passive headgear and gold fronted ones that operate with active noise reduction headgear. In general old headgear works with both kinds of boxes but only gold boxes work with ANR headgear. The EMERs are EMER_L802pt1_Clansman_Radio_Harness_Technical_Description.pdf EMER_L802_Clansman_Radio_Harness_Fault-Repair_Data.pdf EMER_L804_Clansman_Radio_Harness_Field-Base_Repairs.pdf EMER_L806_Clansman_Radio_Harness_Repair_Charts.pdf EMER_L807_Clansman_Radio_Harness_Modification_Instructions.pdf EMER_L809_Clansman_Radio_Harness_Miscellaneous_Instructions.pdf I have to declare an interest as I donated space on one of my servers to host the VMARS archive but all requests should made be via the group website http://www.vmarsmanuals.co.uk after joining ! It should be cheaper than E-Bay for more than 4 or 5 manuals anyway and the technical journal sent to members has many Clansman articles, anyway ! Clansman EMERs differ from Larkspur in that many (most!) do not contain full component level circuits -the contents of the PCBs (called Printed Electronic Circuits) are generally shown as block diagrams only. Apparently the full circuits were used in REME training notes and base repair folders but never released as EMERs. I Having looked at L802 the IB3 diagram is half block and half schematic and the active elements aren't shown in enough detail to identify TR2. L804 basically says how to replace the boards so it looks like they were replace-and-return units as far as anyone who used the EMERs was concerned Probably the best thing is to find someone who can check a working IB3 (ANR) to find out what TR2 is. I'd guess if it got very hot it was the series pass transistor in the voltage regulator and it may be worth looking for a short to ground in the box or harness as well. Regards Iain 73 de G0OZS

The relevant EMERs are available from the VMARS Vintage & Military Amateur Radio society which obtained them under a FOI request. A condition of release was that they are available only to members for private use so it is necessary (and in my opinion worthwhile) to join. I can look up the EMER number later today - I may well have a copy to hand to look up the transistor in question. Regards Iain

Hi Andy Welcome to the Forum - is yours the Champ I saw near the Brantham Co-Op last summer ? Regards Iain

Dear All I am not sure whether this belongs in Electrics, American Vehicles, the non-existent French vehicles topic, for sale or here so I will post it here and let the moderators move it if they think it should be elsewhere. I have a French Simca Marmon SUMB truck with a 2 pin slave / intervehicle connector and a couple of French inter-vehicle cables. The socket on the vehicle has copper contacts flush with the surface and the plugs on the cables have pins about 35mm long. I bought some similar looking sockets advertised as being for M35 trucks etc from a US E-Bay seller which are mechanically similar and mate with my plugs but have deeply recessed contacts inside - about 37mm from front surface to metal as near as I can measure. So there is little or no electrical contact and I can only assume that they were designed not to mate. I am therefore trying to understand why there are two versions, and what the correct version of the socket to replace the rather scruffy one on my truck would be called so I can try to buy one (I'd actually like to buy several, as I want to build a couple of battery packs compatible with my truck for backup starting and to power radio equipment in the field as these seem like ideal screened heavy current connectors ...) I am also open to offers for the 6 NOS ones which turned out not to be what I needed ! Regards Iain

Hi Pete Welcome to the forum! Nice to see a new MV owner in Suffolk - I'm in Brantham south of Ipswich Iain

Towing Label ... note 2320KG rather than 2350 as in my earlier post .. memory is failing I guess

Brake Photos with drums off as promised - there were more but I dont think I kept copies on a PC that survived the death of the phone used to take them

Phil I have been promised some in service photos for my website rebuild but don't have them yet. They are drum brakes with a hydraulic overrun system and a cable parking brake acting on the same cylinder. The cable doesn't have any way to physically move the shoes when the brake handle is released, if the springs won't, which is what caused the problem. I had to take the drums off and reset the shoes, which was a pain because there are no holes for screws to push the drum off the hub in a controlled way If I can find the photos I took at the time, I will post them here. The main antenna was the Racal Granger 4065 broadband fan dipole (I grabbed a screenshot when it was still on the Andrew Antennas web site) with a Racal 15 metre pump up mast - see http://www.g0ozs.org/misc/Racal_457_Mast. There is no ATU. This antenna is untuned and works from 2 to 30 MHz - the price is that a lot of the power ends up in resistive terminations at the ends of the wires which is probably why the Skanti 250W and 750W transmitters (which have a marine heritage) were used. A separate receive only broadband dipole was used with a Racal MA675 9-metre 8 section fibreglass mast for the 2nd radio which was, I think, either receive only or used to manage the data connection only. Skanti did manufacture ATUs for the marine versions of these sets so adding a pair in the place under the front table where the Plessey message handling and link control processors are fitted would probably be a good idea. There is a skanti_radios group on Yahoo which has a lot more technical info on both the NCRS and marine versions. Regards Iain

Hi I had one 3rd hand that had already been stripped. See http://www.g0ozs.org/misc/NCRS Which I will be updating with more radio related detail shortly. Empty they are ok to tow with a LWB landrover if a bit front heavy - equipped please note the label on the side of the tow bar that the towing vehicle must be ballasted to 2350KG - also I understand from someone who knew them in service that there was a 40mph limit. Usually they were towed by LWB landrovers but I think even a Pinzgauer or 101 would need some ballast to make 2350KG? Given that the space inside was smaller than a RB44 box body and the load well under a ton I am not sure why a trailer was used ! One other thing to beware of is that the braking system locks if the park brake is left on for 6 weeks or so - I had that happen to me - always put the feet down and release the brake! I have some photos of dismantling the brake drums somewhere if I can find them! I ended up getting a larger truck and then realising it was bigger inside than the NCRS cabin! Regards Iain